diff --git a/lib/options/rule-indent.js b/lib/options/rule-indent.js
index 5fb76171..470058d0 100644
--- a/lib/options/rule-indent.js
+++ b/lib/options/rule-indent.js
@@ -22,7 +22,7 @@ module.exports = {
      */
     process: function(nodeType, node, level) {
         if (nodeType === 'block') {
-            if (node[0][0] !== 's') {
+            if (node[0] && node[0][0] !== 's') {
                 node.unshift(['s', '']);
             }
             for (var i = 0; i < node.length; i++) {
diff --git a/test/rule-indent.js b/test/rule-indent.js
index 8c44f94a..3826a82d 100644
--- a/test/rule-indent.js
+++ b/test/rule-indent.js
@@ -49,4 +49,11 @@ describe('options/rule-indent', function() {
             'a { /* foo */\n\tcolor:red; /* bar */\n\n\tbackground: #fff\n}\n'
         );
     });
+    it('Valid value should ignore empty blocks', function() {
+        comb.configure({ 'rule-indent': true });
+        assert.equal(
+            comb.processString('a {}'),
+            'a {}'
+        );
+    });
 });